1. Field of the Invention
The invention relates to adhesive bonds and more particularly to recovery of adhesive bond strength within an electronic system.
2. Description of Related Art
For most bonded materials, the adhesive bond strength between a material and an adhesive degrades when exposed to ambient conditions, especially humidity. Extended exposure of the bonded material to humidity can cause degradation of the strength of an adhesive bond between the adhesive and a bondable material. Ultimately, this degradation may result in complete failure of the bond and potential inoperability or destruction of the bonded system.
When an adhesive bond has degraded due to humidity or other ambient conditions, one process of bond strength recovery allows for at least partial, if not complete, recovery of the initial bond strength. This process involves exposing the adhesive bonding material to elevated temperatures of sufficient level to physically and/or chemically affect and enhance the bond between the adhesive and the originally bonded material.
Current methods of submitting the adhesive bond to elevated temperatures, in electronic devices particularly, presents substantial obstacles of both financial and practical scope. Specifically, electronic devices typically are not suited for placement in a high temperature oven. Additionally, the adhesively bonded device may not be readily accessible or extractable from the device. Similarly, the electronic device may be embedded in a larger system and inaccessible for heating purposes or it may be unadvisable to heat the entire system due to other constraints such as heat sensitive materials or parts within the larger system. The labor and system downtime costs associated with the removal and reinstallation of a device or component are likely to be expensive and prohibitive, even if the electronic device were designed for the required elevated temperatures. Furthermore, placing the entire system in a heating source such as an oven could require substantial cost for a large device and heating the entire system might damage other heat sensitive components.
The availability of a suitable heating method poses a substantial downfall to the potential recovery of any current adhesively bonded systems. It is unlikely that a suitable heat source in which an electronic device might be placed for recovery of adhesive bond strength would be found within reasonable proximity of the majority of electronic devices on the market and in use in personal, commercial, institutional, and other functions. The availability of a suitable heat source is further limited when such heat source would require the functionality to monitor the necessary parameters of the bonded system in order to efficiently control the adhesive bond strength recovery.
The prior art specifically addresses very limited, distantly related aspects of this problem of recovering bond strength. For example, a process for detecting the presence of condensation within a device has been presented, but addresses neither the effects of condensation on an adhesively bonded system nor the need or method for recovery of the adhesive bonding strength.
Another process disclosed in the prior art indirectly relates to the problem presented. A method that employs a temperature sensor in the vicinity of a magnetic head is presented to avoid adhesion between a magnetic media and the magnetic head. While the concept of sensing temperature within a device is discussed, it is employed to avoid adhesion between two materials that should not adhere to one another, rather than to recover bond strength of the adhesion between two materials that are purposefully adhered one to the other.
What is needed are an apparatus and process for elevating and controlling temperatures of an adhesive bonding material within an electronic device so as to recover the adhesive bond strength between the adhesive and the bonded material. Such an apparatus and process would benefit from an ability for automatic operation and self-monitoring. The apparatus and process would further benefit from an implementation internal and integral with the adhesive bonding system and device.